College students are especially susceptible to the long-term and short-term health and safety consequences associated with high risk drinking. College students are in an even more susceptible position when alcohol fuels out-of-control parties into riotous behavior, A rather dramatic increase in these "celebratory riots" has been recorded in the United States over the past decade. Universities and communities have increased collaborative efforts to reduce high risk student drinking, but the effectiveness of town-gown coalitions has not been adequately evaluated. Likewise, the role of environmental contexts that either promote or discourage these behaviors is only partially understood. This study a) assesses the impact of the impact of a leadership coalition on environmental changes associated with high risk drinking, b) determines the impact of environmental changes on high risk drinking and off-campus student disturbances, and c) analyzes relationships between high risk drinking and student disturbances. A cohort sequential design using two cohorts of undergraduate students in successive years (n=300 per cohort) will be employed. Alcohol consumption data (7-day recall) will be collected from subjects on 16 different weekends per year, per cohort. Eight of these weekends will be identified as "high risk," eight weekends identified as "low risk" weekends. Time sensitive data (matched to the weekends when subject assessments are made) will be collected on coalition activities, environmental contexts, external reports of high risk drinking behavior, and student disturbances. Analyses of year long trends will be conducted for each cohort. Aggregate analyses combining cohorts will be conduced when necessary and as appropriate. The relationships between coalition activities, environmental contexts, high risk drinking behavior, and off-campus student disturbances will be modeled.